I came up with a little equation that should tell me how many pips a trader can lose before getting a margin call.

We assume that we always go long EURUSD (short would just be the opposite) and our account is in $. We assume that Margin Level for margin call is 100% meaning when Equity = Current Margin Used then you get the margin call.

R = ratio of Initial Used Margin (as a proportion of Balance). R = Initial Used Margin/Balance

L = Broker's leverage

A = ratio of negative (because we are long) change in the rate before we get a margin call.

A = (1-1/R)/(1-L)

For example:

R= 0.5 meaning out of $10,000 balance we will use $5,000 as Initial Used Margin. L=50.

A = 2.0408%

So EURUSD can fall 2.0408% (or rise if we're short) before we get a margin call. If the rate is 1.1117 then this would be equivalent to 227 pips.

Is this correct?

We assume that we always go long EURUSD (short would just be the opposite) and our account is in $. We assume that Margin Level for margin call is 100% meaning when Equity = Current Margin Used then you get the margin call.

R = ratio of Initial Used Margin (as a proportion of Balance). R = Initial Used Margin/Balance

L = Broker's leverage

A = ratio of negative (because we are long) change in the rate before we get a margin call.

A = (1-1/R)/(1-L)

For example:

R= 0.5 meaning out of $10,000 balance we will use $5,000 as Initial Used Margin. L=50.

A = 2.0408%

So EURUSD can fall 2.0408% (or rise if we're short) before we get a margin call. If the rate is 1.1117 then this would be equivalent to 227 pips.

Is this correct?